A lengthy Washington Post article detailed the complex and ongoing concerns with the Conowingo Dam, and the Susquehanna River upstream from it, as major elements in ongoing efforts to remedy Chesapeake Bay water quality concerns.
From the Post article, a focus on the dam’s capacity to trap sediment and nutrients coming from the river flow:
The $19 billion bid to clean the Chesapeake Bay and restore its health rests on a simple plan: cut the amount of nutrient waste — involving nitrogen, phosphorus and sediment — that causes most of the bay’s pollution.
For nearly seven years since the cleanup started, the federal government and six states in the bay’s watershed have reduced municipal sewer overflows that pour nitrogen and phosphorus into rivers that feed into the bay, and cut the fertilizers and other nutrients that run off from hundreds of farms. They also counted on the Conowingo Dam to block massive amounts of sediment in the Susquehanna River from smothering bay grasses that nurture marine life.
But that part of the plan has gone very wrong.
According to a report being prepared by scientists who work for the Environmental Protection Agency program that manages the bay cleanup, the reservoir behind the hydroelectric dam, which sits at the top of the Chesapeake Bay in Maryland, near the Pennsylvania border, has filled with sediment far sooner than the agency had predicted.
Further in the article, Pennsylvania’s relatively lax efforts at water cleanup are identified as a lingering weakness in the multi-state effort across the watershed:
Pennsylvania contributes more nitrogen pollution to the bay than any of the other five states in the watershed. But the Keystone State’s effort to mitigate pollution pales in comparison to that of the others.
To fully recover the bay’s grasses and reduce massive summer dead zones that suck oxygen out of the water and kill wildlife, the EPA and state partners planned to reduce its yearly sediment load by 20 percent, to 6.4 billion pounds, by 2025.
The plan also seeks to limit nitrogen by 25 percent, to 185 million pounds, and reduce phosphorus by 24 percent, to 12.5 million pounds.
Pennsylvania’s effort is so lacking that the nitrogen goal can’t be met.
The EPA recently fired off a letter to the state’s Department of Environmental Protection, ordering it to produce a stronger policy to reduce pollution. The state needs to identify watersheds it has targeted for pollution cleanup, lower the amount of manure that farmers are allowed to use as field fertilizer and spend money to make sure the changes get made.